Example
A 6¾×6¾ Doug Fir-Larch Gluam column, 14 ft tall, fixed at base, pinned at top (Ke=0.8). Axial load 25 kip D + 15 kip Lr (snow). CD=1.25 for snow. Check per NDS 2024.
How StructSuite solves this
StructSuite's free structural design software: select product Glulam, species/grade. Geometry: height, Ke=0.8 (fixed-pinned). Loads: D, Lr with CD. NDS 2024 Supplement Table 5A for glulam Fc, Emin. 6¾×6¾ glulam typically 30–50 kip capacity at 14 ft. Sawn 6×6 would be lower.
Steps
- Step 1: Geometry & End Conditions
Design consideration: 14 ft, Ke=0.8 (fixed-pinned): Le=11.2 ft. Fixed base typical for glulam on pier or embedment. Slenderness Le/d: 6.75 in. d → Le/d=20. Glulam Emin higher than sawn—buckles less for same slenderness. Unbraced length critical for slender columns.
In StructSuite: Open the Geometry section. In the Unbraced length (ft) input box enter the column height. Use the End condition dropdown to select the end fixity (Fixed-Fixed Ke=0.65; Pinned-Pinned Ke=1.2; Fixed-Free Ke=2.4 per NDS 2024 Table G1). Select the column size (e.g., 4×4, 6×6) from the dropdown or size table.
- Step 3: Material & Section
Design consideration: Glulam Fc 2–3× sawn #2 for same dimension. 24F-1.7E: 2400 psi bending, 1.7E stiffness. DF-L Table 5A; SP 5B. No Cr for columns. Wet service reduces; glulam often protected.
In StructSuite: Open the Materials section. Use the Product dropdown to select Sawn Lumber, LVL, or Glulam. In the Species dropdown select Douglas Fir-Larch, Hem-Fir, Southern Pine, Spruce-Pine-Fir, etc. In the Grade dropdown select #2, #1, Select Structural, etc. NDS 2024 Supplement Tables 4A–4D provide Fc and Emin.
- Step 2: Load Definition (ASCE 7-22 / NDS 2024)
Design consideration: 40 kip D+Lr. CD=1.25 for snow (7-day to 2-month). Roof load from trusses, beams. Add L if floor; W, E for lateral. Governing: highest P/allowable. Heavy roof (snow): Lr often governs.
In StructSuite: Open the Loads section. Click Add load case. In the Type dropdown select D, L, Lr, S, W, or E. In the Axial load (lb or kip) input box enter the load. CD = 1.6 for wind/earthquake per NDS Table 2.3.2. Add all applicable load cases. Include self-weight if significant.
- Step 5: Design Verification
Design consideration: 6¾×6¾ glulam at 14 ft: 35–50 kip typical. Sawn 6×6 would be ~15–20 kip at same height. Glulam used when sawn inadequate. Bearing: check base plate or direct bearing. Timber frame: connection design separate.
In StructSuite: Open the Design Verification section. StructSuite checks axial capacity per NDS 2024 Eq 3.7-1 (buckling) and Fc⊥ bearing. Review the D/C ratios. If overstressed, increase size in the Geometry section or reduce unbraced length. Slenderness ratio Le/d ≤ 50 for sawn lumber per NDS.
Live design (pre-filled)
The form below is the real StructSuite module with example data loaded. Display only—values cannot be changed.
Wood Column — Design per 2024 NDS
NDS 2024 Ch. 3 — Solid columns (3.6.2.1) per Section 3.7
Column unbraced length and end conditions per NDS 3.7. Ke affects buckling capacity.
Buckling modes |  |  |  |  |  |  |
| Select mode | ||||||
| Theoretical Ke value | 0.5 | 0.7 | 1.0 | 1.0 | 2.0 | 2.0 |
| Recommended design Ke when ideal conditions approximated | 0.65 | 0.80 | 1.2 | 1.0 | 2.10 | 2.4 |
| End condition code |  | Rotation fixed, translation fixed | ||||
 | Rotation free, translation fixed | |||||
 | Rotation fixed, translation free | |||||
 | Rotation free, translation free | |||||
Le = Ke × L. Use different Le for strong/weak axes if bracing differs.
L1: total unbraced height. L2: unbraced length above intermediate brace. Le = Ke × L.